1. Field
This invention is in the field of toy vehicles, and particularly relates to self-powered ultraminiature toy vehicles capable of negotiating in water as well on steep and irregular surfaces.
2. Prior Art
An amphibious toy vehicle offered at one time by the Eldon Company had the capability of operation on rough surfaces or in water. This vehicle was about a foot long, was driven by a battery-powered mechanism, and had a separate screw drive for propulsion in water. The entire body of the vehicle served as flotation hull.
The Eldon toy suffered from the major disadvantage that its size virtually prevented use anywhere except at a real pond or beach. A suitably sized "water/land terrain" for such a toy should be at least ten or twenty times the length of the toy itself, which in the case of the Eldon toy requires a space essentially the size of an entire room. Thus size itself--or, more precisely, size of the toy in relation to the size of ordinary play areas, especially indoor play areas--can be of great importance in this particular field of toys.
The Eldon toy also had the important disadvantage of depending exclusively upon its entire outer hull for flotation. If the hull developed a leak below the water line, the toy would fill with water and would sink. If the vehicle sank, its drive mechanism would be completely exposed to water and it would shortly rust and in due course become inoperative. In addition the toy had a screw-type propulsion system for operation in water, adding additional complexity and also adding a potential point of leakage--one very likely to be below the water line.
Many water-play toys have been made to resemble boats or water creatures and to propel themselves along the surface of a body of water. Some of these toys depended for propulsion (but not to any significant extent for flotation) upon rotating wheels or other rotating elements rotatably fixed to the sides of the toys. For example, the Tomy Company has offered bathtub toys configured as toy penguins, fish, dolphins, frogs, and so forth, which float and whose limbs rotate to propel them. The same company has offered bathtub toys configured as toy paddlewheel boats, with lateral, rotatably fixed propulsive paddlewheels.
These toys are all made for water use exclusively, rather than for amphibious use. In the case of the paddlewheel toys, it does not appear that the paddlewheels would both at the same time touch a surface on which the toys were placed, and, even if they would, neither the paddlewheels nor the toy bodies generally were suitably configured to provide good traction or effective operation over rough surfaces. In the case of the rotating-limb toys, the dynamic visual effect of such toys operating on a dry surface would be to lurch forward erratically, producing--at best--generally a comic or silly impression.
All of these tube toys may well be adequate for their intended purpose. They would not be suitable for a toy amphibious vehicle that is intended to suggest the operation of a real amphibious vehicle--e.g., a swamp buggy or a military amphibious carrier. Such a real vehicle should operate very tenaciously and effectively over rough surfaces as well as operate in water, to produce an exciting, "adventure" kind of impression rather than one that is comic or silly.